Pulsator for miling machines



1953 F. J. J. J. HENRARD PULSATOR FOR MILKING MACHINES 5 Sheets-Sheet 1 Filed April 8, 1949 Oct. 13, 1953 F. J. J. J. HENRARD PULSATOR FOR MILKING MACHINES 5 Sheets-Sheet 2 Filed April 8, 1949 :0 a my fi w Wm W m 8 4 5 3 2 2 m 1 f M 76 w 7 W J 7 fl a 44 m p w 4 M W W W W I ii. 1 m w Y W 0 .1 52. w 9 W ,l 65 0 f m Mm 4 a w m 2. wo 7 j 4 a g 5 9 3 9 Oct. 13, 1953 F. J. J. J. HENRARD 8 PULSATOR FOR MILKING MACHINES Filed April 8,' 1949 v S Sheets-Sheet s Oct. 13, 1953 F. J. J. J. HENRARD PULSATOR FOR MILKING MACHINES Filed April 8, 1949 5 Sheets-Sheet s llllll.l III III 1\ km ma 1%---- Liii //v van roe; 0v yaw/W0 Patented Oct. 13, 1953 UNITED STATES "PATENT OFFICE 2,655,168 PULSA'IOR FOR MILKI'NG MACHINES Fernand Jean Joseph JulienHenrard, Remicourt,

Belgium, assignor to Ecremeuses Melotte, So-

ciete Anonyme, Remicourt, Belgium, a Belgian company Application April 8, 1949, Serial No.- 86,204 In France May 5, 1948 14- Claims.

um and also two sliding members assuming each.

a reciprocating movement in directions parallel to one another under the action of variations in pressure, one of said sliding members forming a control member while the other produces the alternating connection of the outer chambers of the flexible inflations with the suction means and with the outer atmosphere.

The invention is based on the fact that, in such apparatuses, various causes lead to a gradual slowing down of the frequency of the pulsations and that by reason of the misadjustment of the pulsators now on the market, the pulsations are sometimes too rapid and sometimes too slow but are rarely at the desired frequency.

The factors that may act on the operation and should be considered are as follows:

A. Lubrication The lubrication of the moving members reduces the wear of the ported plates and of the slide valves and also that of the cylinders and pistons. Y n

The reciprocation of the slide valves and the intermittent introduction of air into the pulsator leads the lubricant away from the point at which it is essential towards other points where it is detrimental.

Consequently, at each alternation, the lubricant to be found between the ported plate and the slide valve is sucked together with the dust forming a suspension in the cattle-shed air into the small sized openings and channels .of the pulsator; consequently these openings and chain nels choke up and this produces objectionable congestions preventing the free circulation of air. On the other hand, the lubricant thatis carried along forms deposits on the flexible in-" flations and in the rubber pipes that are thus damaged.

B. Dust The dust forming .a suspension in the air of the cattle-sheds is sucked into the pulsator, soils the ported plates and the slide valves, passes through the small internal channels and forms gradually for a part thereof a deposit round the port controlled by the needle-valve that adjusts the frequency of the pulsations. The free cross-sectional area of this port is thus progresill 2 sively reduced which leads to a slowing down of the frequency of the pulsations.

The slow and inevitable agglomeration of dust round the needle valve is thus one of the causes determining the irregular working of the pulsator.

0. Moisture The moisture of the air in the cattle-sheds condenses by cold weather on the metal parts of the pulsator, the parts that are the most exposed to such a condensation being the slide valves and the ported metal surfaces.

D. Gases The gases contained in the air of the cattlesheds have a corrosive action on the metal parts and add their objectionable influence to that of the water, whereby the ported plates and distributing slide valves are damaged.

E. Adjusting means The poor design of the system of adjusting means for the frequency of pulsation has the highest responsibility as concerns the irregular working met with daily and this leads consequently to a faulty massage of the teats which is highly objectionable and prevents a proper practicable mechanical milking.

The present invention has for its object to remove the different drawbacks enumerated hereinabove, that are inherent to-mostfof the pulsators used nowadays, whatever maybe'their design, and the invention affords an apparatus of a practicable design adapted to bemanufactured on an industrial scale under excellent economical conditions by reason of the fact that pulsatory arrangement with adjusting means showing marks indicating the maximum and mimmum frequency of pulsation so that the operator may adopt as desired the most suitable frequency in the arrangement thus designed.

One of the chief objects of the invention consists moreover in allowing, when required, the removal of the needle valve used for said adjustment without it being necessary to proceed with a further adjustment of the pulsatory arrangement when the needle valve has been returned into its operative position.

According to the invention, the improved pulsator is characterized chiefly by the fact that the supporting block is provided on its upper horizontal surface with grooves or channels and ports for the passage of atmospheric air or for the connection with vacuum, and that said upper horizontal surface of the supporting block carries two removable plate-shaped members lying in superposed relationship while the removable upper plate is also provided on its lower horizontal surface with grooves or channels and is furthermore perforated to form ports, the location of which corresponds generally with those of the ports in the supporting block; the removable intermediary plate that is merely provided with ports is flat and made preferably of a yielding compressible material, the superposition on the supporting blocks of the removable plates allowing the transformation into ducts of the grooves or channels formed on the upper horizontal surface of the supporting block and on the lower horizontal surface of the upper removable plate.

Further features of the invention will appear in the reading of the following descriptio of a complete embodiment of such a pulsator. Said description is given hereinafter with reference to accompanying drawings, wherein:

Fig. 1 is a perspective view of the pulsator in its closed position,

Fig. 2 is also a perspective view of the open pulsatory arrangement showing the chief members forming same.

Fig. 2a is a sectional view of the plate and removable cover of the device.

Fig. 3 is a detail perspective view showing the means connecting up with the outer chambers of the nipples.

Fig. 4 is a vertical cross-sectional view through the longitudinal axis of the supporting block.

Fig. 5 is a detailed cross-sectional View showing the connection between the pipes leading to the outer chambers of the nipples and the milking slide valve.

Fig. 6 is a sectional view that is intended to show the means securing the pusher members of the slide valves to the diaphragms provided on the two opposite sides of the pulsatory arrangement.

Fig. 7 is a perspective view of one of the pusher members.

Figs. 7A and 7B are detail views of a slide valve in perspective view, said slide valve being that used for controlling or else for milking purposes.

Fig. 7C is a vertical cross sectional view that is intended to show a pipe for feeding atmospheric air into the chamber formed above the slide valve.

Fig. 8 is an exploded view adapted to show the different elements forming part of the means adjusting the number of pulsations.

Fig. 9 is a detail view of the inner surfac of the upper removable plate after turning over through 180 with reference to its operative position.

Fig. 10 is a plan view showing the upper surface of the supporting block, the pusher members and pistons being assumed to be removed as well as the device adjusting the number of pulsatlons.

Fig. 11 is a view showing the lower surface of the intermediary plate after turning over through with reference to its operative position.

Fig. 12 is a cross sectional view at an increased scale of the means for adjusting the number of pulsations and of the air filtering means, said arrangement being slightly modified with reference to that illustrated in Fig. 4.

Fig. 12A is a detail view.

Fig. 13 is a diagrammatic view illustrating the operation of the sliding members.

The pulsator includes as a body a supporting block I of rectangular cross-section and the height and width of which are substantially less than its length.

One of the outer surfaces of the block is rigid with a connection 2 adapted for the transmission of depression from a generator of vacuum while a plate is removably secured, say through the agency of a screw 3 on its opposed extreme surface, said plate 4 being provided with a peripheral flange 5 urged against a packing 6 housed inside a slight depression of the block I so as to form a chamber 1 0n the inside of the plate 4 into which chamber open at 8 (Fig. 3) the connecting tubes 9 rigid with the plate 4 and leading to the shells of the milking cups arranged at the outside of the flexible inflations or the like equivalent members so as to submit them alternatively to vacuum and to atmospheric pressure. This operation is obtained by means of a mechanism to be disclosed hereinafter and that acts through a bore I8 (Fig. 5) extending horizontally inside the block I over a certain length and opening into the chamber '1, in order to submit the latter alternatively to suction and to atmospheric pressure.

Each of the longer sides of the block I is rigid with a plate H arranged laterally and the height of which is substantially equal to twice that of the block I so as to produce above the latter and between the flanges formed thereby a chamber llll filled with atmospheric air and closed by a removable cover I2 (Fig.1).

On the other hand, the block is provided on its upper part along each of its small sides with a flange I3 and the space lying between the two opposite flanges serves for housing:

(1) A rectangular member I4 that may be formed by a sheet of a yielding and compressible material such as rubber. Said member I4 may however be made of any other material such as metal, a plastic material or the like.

(2) A rectangular plate I5 of metal or of rigid plastic material showing the same outer outline as the member I4 and superposed over the latter.

These plate members I4 and I5 are removable.

In the upper surface of the block I are formed three grooves 55, I6 and I! (Figs. 10 and 13) that play an important part in the operation of the pulsator and that are closed on the upper side by the plate [4 whereby, at the location of said grooves, the block I and the plate I4 cooperate so as to form said grooves into closed ducts.

0n the other hand, there are formed on the lower surface of the plate I5 two grooves I8 and I9 (Figs. 9 and 13) that have also a part to play in the operation of the pulsator and are closed at their lower part by the plate I4 so that, at the location of said grooves, th plate I4 cooperates now with the plate I5 so as to form also closed ducts.

The plate l5 serves also through its upper face as a slideway for two slide valves 20 and 2| that assume reciprocating movements in parallel directions forming a right angle with the longitudinal axis of the block I.

These slide valves 2fl-2| are constituted by small blocks (Figs. 7A. and '73) having a lower rectangular surface 24 in contact with the ported plate I5 and an upper surface 24 also rectangular but of a smaller size than 24; these slide valves are housed in pusher members 26 (Fig. 7) provided at each end with a lug 21 folded downwardly and provided with a short sleeve 28.

The slide valves and 2| carry on their surface 24 parallel grooves 26 and 26 the groove 26 having a breadth substantially larger than that of the groove 2G and they are held in the corresponding pusher member 26 by small folds 3| formed by the latter and obtained through cutting or stampin and folding over as shown in Fig. 7.

A clearance of about 1 mm. is provided between the pusher member and the corresponding upper surface 24 of the slide valve 29 or 2|.

0n the other hand, the lateral plates II show to either side of their medial axis two recesses 32 (Fig. 2) of circular shape inside the upper part of which are formed openings 33, the lower edge of which is defined by a ridge 34 having a downwardly incurved outline.

The arrangement of the parts as a whole is such that each sleeve 28 of a pusher member lies axially of a recess 32 and may bear against the bottom of the bend formed by the ridge 34 (Fig. 2).

To each lateral plate II is secured preferably by means of screws 35 (Figs. 2 and 6) engaging the sleeves 28, a diaphragm 36 covered in its turn by a side cover 31 that is rigid with the plate I I through the agency of a single screw, not illustrated, or of an equivalent part entering a tapped hole 38 (Fig. 2), in the plate II, after passing through openings 39 and 40 provided respectively in the diaphragms 36 and the cover 31.

The cheeks or plates II are provided at their periphery with a peripheral flange II for housing suitably the corresponding diaphragm 36. The covers 3! are provided with recesses 4| located in register with the recesses 320i the plate II and opening into central hollowed parts 42 so as to form, between each diaphragm 35 and the corresponding cover 3! and in register with the recesses 4| and central hollowed "parts 42, open spaces or chambers (Fig. 6) that are submitted alternatively to the action of vacuum and atmospheric pressure in order to produce the movement on the pusher members 26 and of the slide valves 20-2! as disclosed hereinafter.

The openings 33 allow the passage and sliding of the ends of the pusher members 26 through the plates I I.

The slide valve 20 located on the side nearer the connections 9 is a milking slide valve through which the air chambers of the milking cups are set alternatively in connection with the supply of air and with vacuum, while the slide valve 2| is a controlling slide valve.

Along the longitudinal axis of the block I and inside said block as well as inside the connection 2 is bored a duct 43 that stops short at a small distance from the smaller end of the block I to which the plate 4 is rigidly secured.

Inside the block I are bored vertically starting from its upper surface:

(1) A central part 44 (Figs. 4 and 10) opening into the duct 43 and also into a chamber 45 (Fig. 4) through which the block I fits as known nel 46 of rectangular outline, the cross-sectional area of which is comparatively large and that opens into the pipe 43 at the end thereof.

(3) In register with the controlling slide valve 2|, a vertical channel 41 of small circular cross sectional area opens into the pipe 43 on the side lying between the central opening 44 and the small side of the block I carrying the connection 2.

On the other hand, there open into the upper surface of the block I and in proximity with each longitudinal edge the following channels:

I. Along the front edge, that is the edge considered conventionally as such:

(a) A channel 48 (Fig. 10) directed downwardly along a vertical line in the block I and extending then horizontally as shown at 49 in: Fig. 10 in the latter and in the plate II on the front side of the arrangement, said channel opening finally into the recess 4| corresponding to the milking slide valve through a port 49 formed in the diaphragm corresponding theretoand a groove 55 formed radially inside the recess 4| as shown in Fig. 2.

To the channel 48 is connected the end of the groove I! (Fig. 10) that assumes a bent shape leading to the location of the controlling slide valve and ending in proximity with the front edge considered as asmall circular hollow 5| aligned with reference to the vertical channel 4'! along a perpendicular to the longitudinal axis of the block I.

(b) A channel 52 directed at first vertically downwards inside the block and the front plate II so as to open into the front recess 42 (corre--'- sponding to the controlling slide valve) through a port 53 in the diaphragm 36 and a groove 50 arranged radially in the wall of the corresponding recess 4 I.

II. Along the rear edge:

(a) A channel 54 directed first vertically downwards inside the block I and extending then horizontally at 55 (Fig. 10) inside the latter and inside the rear plate in order to open inside the rear recess 4| corresponding to the milking slide valve.

(12) A channel 55 extending vertically downwards inside the block I and then horizontally at 51 (Fig. 10) inside the rear plate |I so as to open in the rear recess 4| corresponding to the controlling slide valve.

To the channel 56 is connected the groove I6 that after passing round and at a small distance from the central opening 44 between the latter and the outlet of the channel 4'! leads towards the location of the milking slide valve and finishes with a small circular recess 53 arranged in alignment in a direction perpendicular to the longitudinal axis of the block I, with a small recess 59 forming the end of the groove 53 extending over the upper surface of the block I in par-.. allelism with the central channel 43 and leading to aa goint in close vicinity with the central open-- ing At 30 is provided a port opening into the horizontal channel I0 leading to the connections 9.

In the plate I 4 are provided as shown in Fig 11:. (a) Ports 44 46 30 -6I correspondingas to shape and location respectivelyto .theopening latter and inside the .7 44, to the channel 46, to the port 69 and to the port 6| admitting air through the block I as shown in Fig. 7C.

(1?) Small openings 58 59 --4| -l -52 54 corresponding as to shape and location respectively to the recess 58, to the recess 59, to the channel 41, to the recess 51, to the channel 52 and to the channel 54 in the block I.

An opening is also provided at 62 at a location registering with the end of the groove 59 in the block I nearest the central opening 44.

In the plate I5 are provided as shown in Fig. 9:

(1) Ports 44 46 --60 and the air admission port lil corresponding as to shape and location respectively with the ports 44 -46 -450 and with the opening 61 in the plate i4.

(2) Openings 58 --59 4'l 5l and 62 corresponding respectively with the openings 58 59 -4l -5l and 62 in the plate [4.

Moreover, there are provided at B3 and 64 openings lying respectively in alignment with the openings 58 -49 and H -5E in a transversal direction.

On the other hand, the lower surface of the plate [5 shows two grooves I8 and I9.

(11) The groove I8 starts from. the opening 63 and leads to a recess 65 located correspondingly with the opening 52 in the plate i (b) The groove 19 starts from the opening 6!; and ends at a recess 66 located correspondingly with the opening 54 in the intermediary plate Hi.

It will be noticed that the supporting block l and the upper removable plate [5 have their grooves arranged horizontally while the main axes of the ports are normal to the horizontal surface carrying said grooves so as to allow an easy production of said ports through the molding of a suitable metal or thermoplastic material.

Furthermore, the plate l5 should have ports the shape and position of which must be suitably defined whereas the corresponding openings in the intermediary plate 14 and in the supporting block may be somewhat wider and less accurately positioned.

Above the central portion of the plate [5 is located an arrangement for adjusting the pulsator including a cylinder 19 to bottom H of which carries in the example illustrated in Figs. 4 and 8 a hollow rod 72 engaging the central opening 44 in the block I, said hollow rod being held fast by a nut 13 engaging the outer threaded end of said rod 12.

In the example illustrated in Figs. 4 and 8, the cylinder bottom H shows outwardly and at its periphery a groove 14 the bottom of which is provided with openings 15 while said bottom is covere also on its outer surface by a washer 18 that may be made for instance of rubber and has a single peripheral opening 16 and a central opening "5 through which the rod 12 may pass. After mounting the arrangement, said washer "I5 is fitted over the plate l5 in a position such that the opening Hi lies above the opening 62 in the plate [5.

As illustrated in Fig. 12, the cylinder Hi may also be rigid with the plate l5 and the pipe 94 formed in Figs. 4 and 8 by the hollow rod 12 is constituted in this case by a screw 12 provided with a longitudinal bore 94 and screwed inside a tapping of the central opening 44 in the plate IS.

The opening 62 communicates then with a circular groove '11 connected with the inside of the cylinder 10 through peripheral notches 83 of a washer 83 The cylinder 10 is closed at its upper end by a cover 18 bearing against the upper edge of this cylinder but showing a peripheral tubular projection l9 outwardly threaded so as to be screwed into the upper tapped part of the cylinder ID. This cover carries centrally a needle valve passing through it and including a cylindrical threaded portion followed by a smooth cylindrical part 8| from which is cut on the lathe the terminal portion 82 that is very slightly tapering for the reasons disclosed hereinafter.

Round the needle valve 80--Bl82 is provided a sleeve or nozzle member 83 the bore of which has at its upper end a diameter corresponding to that of the smooth part M of the needle valve. The lower end of this sleeve 83 finishes with a nozzle forming a mere adjustable opening 85 round the needle valve end 82 and also an empty space 84 surrounding said needle valve and communicating with the inside of the cylinder 10 through two coaxial openings 84.

At its upper end, the sleeve or nozzle member 83 carries a flange 86 through which it engages a recess 8'! in the cover 18.

Above the cover 18 is provided a locking nut 88 resting on the upper surface of said cover with the interposition of a washer 89, e. g. of leather.

The rod 81-82 ends at its upper end with a knurled head 90 with which a mark carrying disc 91 is rigid.

The threaded portion 80 of the needle valve is screwed into the cover 1'8 and nut 88 between which is inserted as stated a washer 89 of leather or the like soft material adapted to prevent any undesired unfastening of the nut 88.

It will be readily understood that through this arrangement the air entering the cylinder through the port 52 may be sucked into the duct 43 through the openings 84, the bore 84 the adjustable port 85, and the bore 94 or 94 in the hollow rod 12 or in the screw [2 Fig. 12 shows moreover that there may be provided means for air filtering including preferably a double filter constituted by:

1. A first filter that is a felt or cotton wool cylinder 95 through which the stream of air flows from which the dust is to be removed and that serves for holding back the large dust parti- 0 es.

2. A second filter constituted by a wound strip 96 constituted by fine-mesh canvas, housed between two coaxial removable cylinders 91 and 98 fitted round the sleeve or nozzle member 83 and perforated at 99 in such a manner that the air may be brought under depression through said openings 99 and the strip 96 before reaching the opening 85.

The operation of the pulsator according to the invention is as follows (Fig. 13)

The pulsator is connected with the general suction pipe through a rubber hose fitted over the connection 2.

The depression acting inside the pulsatory arrangement is a constant one because it is adjusted and kept at a predetermined value through the operation of a valve (not illustrated) inserted in the general suction pipe.

This constant depression is apparent in the duct 43, the channels 46-41 and 94 or 94 while there prevails in the hollows 5!, the ports 64 and 6B, the grooves ll and I9 leading to the diaphragm chambers 4! at A and B alternatively a depression equal to that in the duct 43 and a pressure equal to atmospheric pressure, according to the position occupied alternatively by the valve 20 at A and B and by the valve 2| at C and D (Figs. 4 and 13).

The letters A-B-C-D define the extreme positions of the pusher members.

The recess 59 (Fig. 13) is submitted to the action of a depression that is purposely reduced through the fact that the air passing through the channel 94 or 94 passes round the throttling needle valve 82 (Fig. 12) when coming from the filtering chamber in the cylinder and through the port 62, the duct 50 and the recess 59 (Figs. 4 and 13).

Through this recess 59 (Figs. 4 and 13) the reduced depression is applied alternatively through the ports 63 and 58 (Fig. 13) and the channels l8 and i6 (Fig. 13) to the rear side of the diaphragms 36 at C and D.

Similarly the maximum depression that is equal to the prevailing in the channel 43 is exerted alternatively through the ports 64 and 5| (Fig. 13) and the corresponding channels l9 and I! (Fig. 13) on the rear surface of the diaphragms 36 at A and B.

It is well known that in all pulsators, the association of the action of air at atmospheric .pressure and of a partial vacuum produced by the vacuum pump defines the driving power .producing the shifting of the movable members of the pulsators such as diaphragms, .pusher members and slide valves.

In the present case, the movable members include two pusher members 26 (Figs. 247 and 13) both of which are connected through their ends with the two lateral diaphragms 36 (Figs. 2-6 and 13) These two diaphragms form with the twolateralcovers 31 four chambers 4| (Fig. 13), that is two chambers per pusher member.

One of these chambers is submitted to depression while at the same time the opposed chamber is submitted to atmospheric pressure. Consequently the pusher member moves in the direction of the resultant of said two actions.

During its displacement, the left hand pusher member 26 carries along with it the slide valves and the right hand pusher member 26 carries along with it the slide valve 2| as shown in Figs. 7A and 13.

Considering (Fig. 13) the left hand slide valve at the end of its stroke at B while the other slide valve 2| has reached the end of its stroke at D, the groove 26 of the left hand slide valve 20 provides for communication between the recesses 58 and 59 while at the same time the port 63 is uncovered and submitted to the action of atmospheric pressure.

In this position B of the slide valve .20, the action of a partial vacuum is felt in the duct l6 and reaches the outer surface ofv the diaphragm 36 in the chamber 4| corresponding to C which leads to a shifting of the slide valve 2| towards the end of its stroke at C.

When the slide valve 2| has reached this position, it connects the groove 26 in its contacting surface the ports 64 and 61 whereby maximum depression is exerted through the .pipe IS on the rear surface of the diaphragm 36 at A in the chamber 4|. At the same time, the port 5| is uncovered by 2! so that the atmospheric air enters same and reaches through the pipe I! the chamber 4| behind the diaphragm 36 at B which leads to a shifting on the slide valve 20 from B to A, which latter position is shown in dotted lines. The operation described begins overagain 10 during the whole working of the pulsatory arrangement.

It is apparent from the above that under the simultaneous action of depression and atmospheric pressure, one of the two pusher members, say that on the left hand side, is brought to the end of its stroke at B which produces then the shifting towards the end of its stroke of the other right hand side slide valve towards C which in its turn produces the shifting in the opposite direction, that is towards A, of the first left hand slide valve and so on.

The desired frequency of pulsation or the number of displacements per minute of the slide valves is adjusted by acting through the needle valve 8||8|82 on the suction exerted through a double filter on the air admitted in alternation from the chambers bounded by the diaphragms C or D. Said suction is exerted at 0 through the pipe l6 up to the recess 58 and thence through the groove 26 located underneath the slidevalve 20 and said suction reaches the recess 59 and the channel 59, the filters and finally the periphery of the adjusting needle valve before the air enters the main pipe 43; on the other hand, when the slide valve 2| has been shifted, the air sucked out of the diaphragm chamber D passes into the channel l8 up to the opening 63 through which it reaches through the same groove 26 underneath the slide valve 20, the opening- 59 and the channel 56 so as to again reach the main pipe 43 through the two filters and the peripheryof the adjusting needle valve.

It is therefore the frequency of the movements of the right hand slide valve 2| that is actually adjusted by the action of the threaded needle Valve and this slide valve generally termed the controllin slide valve adjusts'the frequency of movement of the left hand slide valve '20 or pulsation slide valve.

It will be readily understood by way of consequence that only the air contained alternatively in the diaphragm chambers 4| at C and D may pass through the double filter and round the adjusting needle valve at the moment of the alternating setting of these two chambers under depression.

The considered pulsator has only two diaphragms in all for the four ends of the two pusher members and each diaphragm acts simultaneously in opposite directions on two ends of the pusher members.

At A and B, the diaphragm submitted alternatively to atmospheric pressure and to a maximum depression that is equal to that appearingin the main pipe 43 respond more energetically and more speedily than at C and D where only a reduced depression appears alternatively with atmospheric pressure. Consequently, 'there are produced more energetic alternating movements of the pusher memher and slide valve located between A and B, that are submitted to the maximum depression, as compared to the less energetic and less speedy action exerted on the slide valve and pusher member located between C and D.

By reason of the energetic reciprocating displacements of the slide valve 20, it is possible to obtain a more efficient massaging of the udders of the cows and in view of the presence of the air ports 46 and 60 (Fig. 13) of Wide section,

the air circulates freely and with a maximum energyfrom the chamber located between the teat- 11 cups and the flexible inflations up to the main pipe of the pulsator.

The reduced depression acting on the diaphragms at C and D defines for the pusher memof the movements of the right hand slide valve that controls the movements of the left hand slide valve and defines thus the frequencies of the pulsations of the apparatus.

The frequencies of the pulsations range normally between 40 and 60 per minute. The sole part to be played by the pulsator consists in alternatively submitting to pressure and to atmospheric pressure the chambers located between the teat-cups and the flexible rubber inflations.

In practice, the movements of the slide valve are not performed as smoothly as supposed hereinabove.

This is due in particular to the fact that the outer air fed into the pulsator is always that of the cattle shed and is therefore laden with dust, steam containing sometimes ammoniacal compounds and also carbonic gas; By reason of the four diaphragm chambers, the different pipes and the chambers located between the teat-cups and the rubber flexible inflations are filled at each complete cycle that is forty to fifty times per minute with such soiled and moist air, it will be readily understood that the moving members of the pulsator are submitted to the objectionable action of said soiled air.

To obtain a perfect mechanical efficiency for the moving parts of the pulsator and thereby to assume a regular, permanent and reliable operation, it is necessary to remove the drawbacks inherent to the unavoidable use of more or less soiled air from the cattle-shed for the actuation of the pulsatory arrangement.

To this end, and according to the invention, the following steps should be taken:

(1) The air is submitted to a preliminary filtration before it is admitted into the chamber inside which the slide valves operate and, to this purpose, taking into account the fluid tightness of the cover, there is provided in the support I of the arrangement a channel 6| opening on one hand into said chamber and, on the other hand, under the arrangement through its lower surface 95; inside this channel is inserted a removable filtering pad 51 (Fig. 7C).

, According to requirements, there may be provided a plurality of such channels 6| with a preliminary filter or else the cross section of the prelliiilnary filter provided may be increased. Thisfchannel or these channels 8| open into the lower surface of the block I at one or more locations protected against the dust that may drop onto the pulsator during its operation.

(2) There should be used for the slide valves and the distributing facing or plate a material that is unaffected by air moisture at the temperature of operation as well as by ammoniacal vapors and/or carbonic acid. Moreover, it is necessary that the steam should not condense in cold or wet weather on the slide valves or the cooperating ported surface where it would form with the dust carried by air minute particles of 12 sludge that would detrimentally interfere with the operation of the arrangement and for this reason it is necessary to make use of a material that is a poor conductor of heat.

Heretofore in known pulsatory arrangements, these various parts or at least one of them was of metal, the other one being possibly made of thermoplastic material. According to my invention, on the contrary, the slide valves and cooperating plate are all of amaterial that is not heat conductive.

(3) Moreover, as the diaphragms are made of natural or synthetic rubber, with or without the insertion of a medial thin sheet of fabric such as silk or the like material, it is necessary to obtain self -lubrication so as to remove the necessity of external lubrication.

The material used for the ported plate and the slide valves should therefore be constituted by self lubricating material so as to avoid the formation between the slide valves and the ported plate of an emulsion of oil, water and dust than can be carried along into the diaphragm chambers where it would damage the diaphragms or into the'filters that it might clog.

In order to answer the conditions defined hereinabove, at (2) and (3), it is of advantage to use for instance for one of the cooperating parts a cast phenol base resin and for the other a-graphitised phenol base resin or else it is possible to use a graphitised phenol base resin for both members. According to a modification, the slide valves 20 and 2! may be made of thermoplastic material and the ported plate 15 of metal, but in this case there is fitted into or glued to the plate portions over which the slide valves move, two strips I06 (Fig. 12) of a self-lubricating thermoplastic material that is a poor conductor of heat.

(4) Experience has shown that the needle valve that is essential for adjusting the frequency of the pulsations, is the member that has the most serious action on the regularity of operation of the pulsator because the free space between the tip 82 of the needle valve and the opening to be adjusted, that is the bore 94 or 94 is so small that the minute dust particles that may pass through an ordinary air filter may yet adhere to the tip of the needle valve by reason of the sudden change in direction and the throttling action to which the air is submitted at said point, whereby dust speedily accumulates to an extent such as will reduce the cross-sectional area of the passage, and brake more and more the air from the diaphragm chambers C and D until the depression has no longer any action, whereby the reciprocating movements of the right hand controlling slide valve are slowed down to substantial stoppage which corresponds to a gradual reduction in the number of pulsations and finally complete stoppage of the arrangement. This gradual reduction of the frequency of pulsation has for its result, if care is not taken, that the frequency of massaging of the udders becomes insufficient and leads to a congestion of these parts and consequently to serious physiologic troubles for the milch cows thus mechanically milked. I

To remove completely this serious defect of the pulsator, there is provided a specially designed filter adapted to retain dust particles of microscopic size that may enter the chamber located above the slide valve in spite of the presence of the preliminary filter pad at GI and also the dust from the chamber lying between the metal teat cup and the flexible inflation.

This filter includes a small perforated tube 98 round which a ribbon 9B of closely woven fabric is wound about thirty times to form thus a circular filter through which the most minute particles of dust cannot pass. This wound ribbon is protected outwardly by a second perforated cylindrical tube 97 and this forms a small compact system that is fitted inside the cylinder 19.

The two metal cylinders 91 and 98 and the wound ribbon 96 rest through their lower end on the rubber washer 83 that in addition to the part played as a packing compensates for the small possible difference in height between the two metal cylinders 91 and 98 and the member 83 forming at its lower end a nozzle round the needle valve.

The air from the diaphragm chambers C and D, before it passes over the last filtering ribbon 96 (Fig. 12), has passed through a filtering sleeve of cotton wool or felt 95 (Fig. 12).

If, after several months of operation, the last filtering ribbon is clogged or if for any other unforeseen reason, the result is reached, the pulsator would assume a lesser number of pulsations per minute and the operator might without any difficulty provide for the replacement of-the filtering ribbon. It is also possible for an operator to inadvertently remove the filtering ribbon or to forget its replacement inside the arrangement after dismantling of the latter or else it may happen that the operator has no spare filter available. In such a case, the tip of the needle valve would become laden with minute dust particles leading to a reduction in the number of pulsations.

To prevent this anomalous operation:

(5) The needle valve system may be removed as a whole without any modification in the adjustment of the pulsatory arrangement so as to allow the operator to return it into its original condition after rubbing between his fingers the soiled tip of the needle valve, which may be done in less than half a minute.

To this purpose, it is sufficient to unscrew the nut 18 without touching the knurled knob 99, to remove the system including the parts 90-9l 92-88-89 and 18, to clean with the fingers the tip of the needle valve 82 and then to screw home the nut 18 (Fig. 12) carrying said system of parts 999|92-8889 and i8.

A considerable advantage of the pulsatory arrangement according to the invention consists therefore in that the dismantling may be performed without any modification in its adjustment.

With the known prior arrangements, the adjustment of the number of pulsations to be executed after using the arrangement a few hours is a tedious business for the operator who is generally a farm servant possessing no suitable means for measuring time, chiefly when this adjustment is to be performed in the cattle-shed at milking time. Thus nowadays the adjustments performed at the farm are uncertain and are limited to a rough adjustment of the number of pulsations which is detrimental for the proper operation of the mechanical milking. With the means disclosed above and whatever may happen to the filtering ribbon, it is possible to immediately replace it or do away with it even during the milking without it being necessary to resort to a further adjustment of the desired number of pulsations per minute.

(6) The tip 82 of the threaded needle valve is given an extremely reduced tapering in order to obtain a slight modification in the free crosssectional area of the bore for a comparatively important vertical displacement of the needle valve 89 and thereby an increased extent of the adjusting sector of the plate 91. As illustrated in Fig. 12, the needle valve 99 including a knurled head 90 has its end slightly tapering in a manner such that the angle at the base of the cone may measure between 89 and 89 30'. This terminal portion of the needle valve is shifted vertically, by screwing or unscrewing, inside the cylindrical opening 85 (Fig. 12) so that it is possible to reduce or increase mi-crometrically the cross-sectional area allowed for the passage of filtered air from the diaphragm chambers C and D. 'Thus, when screwing down the needle valves 89 through actuation of the head 99, the throughput of air passing through the opening 85 is gradually restricted whereas, when unscrewing the knurled head of the needle valve 89, the free passage allowed increases so as to provide an increase of the throughput of air sucked in and consequently of the number of pulsations.

By reason of the very small conicity of the needle valve, it is necessary to rotate it through a large angle to obtain a substantial modification in the cross-sectional area left free between the periphery of the opening 85 and the needle valve 82. Consequently the accurate adjustment of the number of pulsations becomes a very easy matter.

This arrangement allows moreover engraving marks on the upper surface of the disc 9| (Fig. 12), that are brought readily in front of a stationary mark carried by the ring 92 that is fitted inside the nut 18 through the agency of the stud 93, said mark giving out the normal minimum and maximum frequencies of pulsation to be adopted by the operator of the mechanical milking machine.

Between the minimum and maximum frequencies that are provided the operator may choose instantaneously the frequency that is the best adapted to the cow that is being milked.

The parts 898899 and 19 in Fig. 12 form a rigid system wherein it is possible however to execute a shifting of needle valve 89 through action on the knurled head 99, the rotation of which requires a certain effort as required for preventing any fortuitous undesired shifting of the needle valve. The nozzle member 93 surrounded by the ribbon filter described hereinabove is fitted freely inside the opening provided to this purpose in the part 18 after the latter is screwed into the cylinder 19 that may be in one with the ported plate [5.

The cover 18 is locked by screwing against the upper edge of the cylinder 19 and as, on the other hand, the nozzle member 93 bears completely inside the recess provided in said cover member 19, the position of the opening 85 remains unvarying with reference to the terminal portion of, the needle valve when the system considered is fitted again in position.

At I95, the shank of the needle valve carries a small plate whereby, if the operator omittedinadvertently reinserting the ribbon filter and the sucked in air were laden with dust, most of the dust particles would form a deposit at 84 over the small plate at the point where the air is constrained to assume a sudden change in direction. This latter feature of the needle valve does not prevent the gradual clogging of the opening 85 but at least it delays it for a very long time. The cap 92 that is fitted for instance as stated is? by means of a stud 93 in the upper portion of the cover member 18 and the upper level of which is substantially flush with the lower level of the disc 9| carries marks corresponding to the range of normal frequencies in which the operator chooses that which is the most suitable. The

cap 92 prevents also any fortuitous contact with the nut 88 when operating the knob 99 so as to prevent any undesired release. From the above, it is easy to ascertain that the opening 85 remains free permanently by reason of the filters of a special type already disclosed, and the possibility of wiping the tip of the needle-valve and reinserting it without any modification in the adjustment to predetermined number of pulsations.

All the pulsators now on the market require very frequent readjustment by reason of the gradual closing in of the needle valve opening and of the impossibility of cleaning the latter without it being necessary to again adjust the frequency of pulsation.

The cover 52 of the chamber :s; of the pulsator into which the air enters after a preliminary filtering in the opening 3! may provide for fluidtightness of said chamber mi through the agency of a plate I02 of rubber or the like yielding ma.- terial. This plate may also be made of felt in which case it acts as a prelii inary filter. This yielding plate Hi2 forms a packing that is held against the cover of the arrangement by an inner metal sheet I03 bent to match the shape of the cover l2. When the plate is made of rubber, the cover 52 is completely fiuidtight. When it is made of felt, the fiuidtighiness is longer ensured but the air entering thus the chamber in addition to or possibly instead of the air entering through the channel or channels can only be air that has been previously filtered and enters through the whole periphery of the cover.

As illustrated in Fig. 2A, the rubber plate Hi2 may rest on the inner flanges I02 formed by the plates 1 l and it is enclosed by the cover 42.

The use of diaphragms allows obtaining the advantage, that is well known per se, of avoiding any use of a lubricant as would be necessary in the case of piston operation.

However, in all known arrangements of the same type, each piston has been replaced by one diaphragm whereas in the case of the present invention the four pistons have been replaced by two double diaphragms, which means an advantageous simplification.

To form such diaphragms, thin sheets of rubber are generally used but according to the invention, it is of advantage to use a rubber sheet containing in its medial plane a thin sheet of fabric, preferably silk, so that the diaphragm may retain its yieldingness while its elasticity is reduced in order to prevent any deformation during operation.

The brittleness of thin yielding rubber diaphragms appears after a certain time of working and leads to damages that cannot be foreseen and that appear or are found out unfortunately only during the operation of the pulsatory arrangement, that is when milking in the cattleshed or in the fields.

Obviously, the operator should then, during the milking, replace as speedily as possible the diaphragm or diaphragms that are no longer operative.

The finding out of the faulty diaphragm with a view to replacing it requires often the disman- I! tling of the four diaphragms equipping the major part of usual pulsatory arrangements.

This finding out of the faulty diaphragm implies the removal of number of screws and when the diaphragm is replaced by a new one, it is necessary to again set in position and screw home the same number of screws, which may be as high as three or four screws per diaphr-gm.

This loss of time during the milking is considered by the operator as the greatest drawback of diaphragm pulsatory arrangement.

To reduce this drawback and to prevent any objectionable consequence thereof, I have adopted in the case of the invention the two double diaphragms, that is each or" the two diaphragms carries two pusher members and is sealed tightly by a cover held by a single screw so that it is required to remove at the maximum two screws before finding the defective dia phragm. The latter is moreover very easily replaced.

From a constructional standpoint, it should be mentioned as a further advantage the fact that the slide valves 26 and El are independent of the pusher members and that a clearance is always left between the upper surface of a slide valve and the corresponding pusher member whereby the proper bearing of the slide valve on the ported plate l5 does not depend on the proper positioning of the pusher members or on the possible deformation of the diaphragms that are generally thin and carry the heads of the pusher members, the position of which depends on the other hand on the diaphragms.

What I claim is:

l. pulsator of the flexible diaphragm-type having an air outlet at one end adapted to connect to means for producing sub-atmospheric pressure and having at the other end an air inlet adapted to connect to means for utilization of said sub-atmospheric pressure, including a horizontally disposed block provided with laterally disposed fianges, a plurality of flexible diaphragms carried by said flanges, and a first cover of which the longitudinal edges make contact with the peripheries of said flanges so as to enclose a space between said block, said first cover and the portions of said flanges which extend beyond said block, a pulsation frequency determining and adjusting element located within said space and having manually controllable adjusting por tions thereof, projecting exteriorly of said space, said block carrying two slide valves each capable of reciprocating movement in directions parallel to one another and transversely to the length of said block, under the influence of variations in air pressure, one of said slide valves acting as a control member whilst the other valve acts to connect said inlet alternately to said outlet and to atmospheric pressure, said block being provided with channels for the passage therethrough of air in alternative directions, said flanges having therein depressions for the deflection therein of said flexible diaphragms and means for carrying said diaphragms, pusher members afiixed to said diaphragms and each mounting therein a slide valve, said flanges being provided with openings for the reciprocatory movement therein of said pusher elements, and each flange carrying thereupon a respective side cover, each of said covers being provided with twin hollow chambers, respectively positioned opposite said flange depressions, whereby are formed four diaphragm chambers, with which the respective diaphragms cooperate.

2. A pulsator according to claim 1, in which said channels in said block are provided with ports cooperating therewith, and in which there are provided two removable plate members horizontally disposed and lying in superposed relationship upon said block, the upper plate serving to support said slide valves and being provided on its lower surface with channels and being provided with apertures so located as to register with the corresponding said ports in the supporting block, the intermediary plate being provided with ports only, and the superposition on the supporting block of the removable plates allowing the transformation effectively into ducts of the channels formed on the upper horizontal surfaces of the supporting block and on the lower horizontal surface of the upper removable plate.

3. A pulsator according to claim 2, in which said slide valves are movable independently of said pusher members, and including means for mounting said pusher members so that a clearance is left between the upper surface of a slide valve and the corresponding surface of a pusher member, whereby to improve the bearing of said slide valves upon the upper ported plate.

4. A pulsator according to claim 3, in which the slide valves are constructed of self-lubricating thermoplastic material, whilst the ported plate is constructed of metal, and has attached to a portion of the surface thereof relatively small plates of self-lubricating thermoplastic material, having relatively low thermal conductivity, said plates being located upon said metal plate at the positions where said slide valves move, whereby sliding takes place over said smaller plates.

5. A pulsator according to claim 4, in which the device used for adjusting the frequency of the pulsations includes a cylinder rigid with the upper removable ported plate and means placing the inside of said cylinder in communication with said air outlet, said cylinder being alternately put into communication with one of the diaphragm chambers of the controlling slide valve and including a cover for this cylinder and a threaded stem the end of which forms a needle valve, said stem being screwed into said cover.

6. A pulsator according to claim 5, in which the extremity of the needle valve is slightly tapered and including means for moving said needle valve vertically, said means including an outer knob situated at the extremity of said threaded stem of said needle valve.

7. A pulsator according to claim 6 in which, above the cover of the cylinder forming part of said adjusting device, the threaded stem of the needle valve is provided with a lock nut, thereby forming a unit which substantially comprises said cover, the lock nut, the threaded stem, and the knob of said stem, there being also provided a disc carrying indicia and located at the upper part of the threaded stem.

8. A pulsator according to claim '7, in which the adjusting device includes removable means 18 to filter the air coming from the diaphragm chambers.

9. A pulsator according to claim 8, in which the adjustment device is provided with a second removable air filter, including a perforated tube, a closely woven canvas ribbon, wound over said tube, a second perforated tube fitted over said wound canvas ribbon, and a central sleevemember, provided with a nozzle at its lower part, around which said filters are positioned.

10. A pulsator according to claim 9, which includes a washer under the lock nut on the stem, whereby to prevent any untimely'release of said lock nut, said washer being clamped between said nut and the cover, soas to exert a braking action on said cover, the relative positions of said members being modified only when the cover is unscrewed from the cylinder and when the cover is replaced thereon.

11. A pulsator according to claim 10, in which the nozzle is provided with a removable sleeve, the cover has a recess and said sleeve engages said recess of the cover in such manner that the dismantling and mounting of the cover are without influence upon the position of the needle valve in the nozzle.

12. A pulsator according to claim 11, in which is provided a ring fixed into the cover of the cylinder, forming part of the adjustment device, and having an indicium, and in which a disc is carried by the upper end of the threaded stem and is provided with two indicia indicating, respectively, the normal minimum and maximum frequencies of pulsation.

13. A pulsator according to claim 12, in which is provided upon the shank of the needle valve a small plate, for retaining most of the dust particles, if the pulsator is operated without being provided with the filtering means of the adjustment device.

14. A pulsator according to claim 13, in which there is provided below the sleeve member a compressible washer, which, when compressed, causes said sleeve member to be held applied againstthe bottom of said recess formed in the cover, whereby this washer, while forming a tight closure at the base of the two filters, compensates for the diiferences in height which may take place, during manufacture, between the perforated cylinders by which one of the filters is surrounded and the upper fiange of the sleeve-member forming the nozzle.

FERNAND JEAN JOSEPH JULIEN HENRARD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,844,853 Hodsdon Feb. 9, 1932 1,875,083 McCornack Aug. 30, 1932 2,017,754 Hodsdon Oct. 15, 1935 2,129,765 Hodsdon Sept. 13, 1938 2,464,917 Babson Mar. 22, 1949 

